Holddown for ladders



Jan. 25, 1955 TRQCHE' 2,700,527

HOLDDOWN FOR LADDERS Filed March 6, 1955 2 Sheets-Sheet 1 INVENTOR 2 T HERMAN J. TROCHE ATTORNEY Jan. 25, 1955 H. J. TROCHE 2,700,527

HOLDDOWN FOR LADDERS Filed March 6, 1955 '2 Sheets-Sheet 2 II I - W 9 M f \1 i: Q P I H o 1: INVENTOR Y i: HERMAN J. TROCHE 1: l BY I I II 1 5E ig" N A W ATTORNEY United States Patent 2,100,527 HOLDDOWN FOR LADDERS Herman J. Troche, Fairview Park, Ohio, assignor to J. H. Holan Corporation, Cleveland, Ohio, a corporation of Ohio Application March 6, 1953, Serial No. 343,019

2 Claimsr (Cl. 248-361) The invention relates to clamps and particularly to devices of this character utilized as ladder clamps while transporting ladders. Such clamps are known as Hol ddowns in the trade and the improvements therein (118- closed by the instant application are shown applied to a two-section pivotally-secured aerial ladder designed for use on a utility truck body and transportable 1n telescoped and clamped condition on the body when not 11] use.

The ladder is extensible and rotatable and can be elevated to any desired elevation up to about seventy-five degrees, these movements being effected by controls mounted on the body and governing an Oil pump actuated by engine power take-01f or power otherwise suitably obtained.

The holddown herein shown and described operates entirely automatically to clamp the ladder to the truck body upon lowering of the ladder to transporting position and to release the same upon any material movement of the clamped ladder toward elevated position. Such automatic unclamping is particularly important for protection of the ladder and other equipment used in ladder opera tion. Ladders are usually clamped for transporting by some kind of manually-actuated holding means and it frequently happens that an attempt is made to raise the ladder without first unclamping these holding means. Such action strains the involved equipment and, in the case of ladders used as utility truck equipment and actuated by considerable power such as high pressure oil, may result in heavy damage.

The annexed drawings and the following description set forth in detail certain means illustrating the instant improvements in holddowns, such drawings and description disclosing, however, only one of the various forms in which the improvements may be embodied.

In said annexed drawings:

Figure 1 is a side view of the improved holddown mounted upon a utility truck body in the clamped transporting position of the ladder, the truck cab and body being indicated by dot-and-dash lines;

Figure la is a side view of a major portion of the extended ladder in about a maximum elevated position, the view indicating approximately the position of the ladder if elevated from the truck position shown in Figure 1;

Figure 2 is a fragmentary plan view, upon an enlarged scale, taken from the plane indicated by the line 2-2, Figure 1, the lower ladder section being suggested by dotand-da-sh lines;

Figure 3 is a vertical fragmentary section, upon a greatly enlarged scale, taken in the plane indicated by the line 3-3, Figure 2, the ladder and holddown parts being shown in the respective positions which they occupy when the ladder is clamped; and

Figure 4 is a view similar to Figure 3 but showing the respective positions of the several elements when the ladder is released.

Referring to the annexed drawings in which the several elements are indicated by the same respective numbers in the several views, a truck body 1 has a working floor 2 upon which is supported a ladder mount 3 equipped with controls 3 for elevating, extending, and rotating a two-section ladder by oil pressure supplied by a pump (not shown) powered by an engine take oif or any other suitable source of power. The truck cab is indicated by 7.

The ladder is of the telescoping type having a lower outer section 4 and an upper inner section 5. The con- 2,700,527 Patented Jan. 25, 1955 "ice cern herein is only with the lower outer ladder section 4 and its side rails are indicated by 6.

One of the improved holddowns is utilized at each side of the cab 7, adjacent the roof thereof, the central portion of the telescoped ladder resting on a support above the cab roof when the ladder is clamped for transporting and the bottom ladder end resting on the'mount 3 to the top of which it is pivotally secured. The ladder section 4 is also rotatably secured to the mount 3 for rotatable movement of the ladder in a horizontal plane through 360 degrees.

Mounted above the top of the cab 7 is a transverse channel member 10 having a rear open side to the inside upper and lower flanges of which are welded the front ends of a supporting member 24 which is rearwardly extended and downwardly sloped for mounting on the body floor 2, the member 24 having a vertical brace 24' mounted on the floor 2 adjacent the front end of the body 1.

The side rails 6 of the lower ladder section 4, which are preferably of wood structure, are seated at the bottom on, and bolted on the outer side to, metal reinforcing channels 8 which rest, when the ladder is in its lowermost position, upon rubber blocks 9 bolted to the top of the cross channel 10, Figures 3 and 4.

Also welded to the top of the cross channel 10, on each side of the center thereof, and exteriorly of the ladder rails 6, is a cover 16 for the holddown mechanism and, inasmuch as this mechanism is the same on both sides, only one will be described in detail. These covers 16 extend down to the bottom of the channel 10 and are Welded to the flanges of the latter.

Bolted at its top end to the top of the channel 8 is an angular bracket 11 which is also bolted adjacent its lower end to the channel 8 and the ladder rail 6. The same lower bolt 25 secures the ladder rail 6 in and to channel '8. This bracket 11 is bent'in opposite directions between its ends to form a downwardly and inwardly inclined part 13 and an upwardly and inwardly comparatively sharp inclined part 14. The surfaces of these bracket parts 13 and 14 act as cam surfaces upon a spring-pressed roller 22 of a latch lever 18 during the automatic fastening and unfastening of the ladder section 4.

The latch lever 18, which is a channel member, is pivotally mounted adjacent its lower end on a bolt 19 secured in the front and rear face members of the latch cover 16 which latter has an open inner side 17 through which extends the elbow formed by the bracket parts 13 and 14. The base of the channel lever 18 and the inner face of the outer side of the cover 16 serve as abutments for the ends of a compression spring 20 mounted on a bolt 23, which spring 20 tends to move the upper end of the latch lever 18 inwardly whereby the roller 22 mounted on a pin 21 in the lever 18 can contact the inclined surfaces 13 and 14 of the bracket 11. When the ladder section 4 is in its lowermost rested position, the roller 22 engages the sharply inclined part 14 of the bracket 11 and serves to hold the ladder 4 down. This cam surface portion 14 forms a recess 26 in which the roller 22 lies and bears down upon the bracket 11 to hold the ladder locked. The hole 15 in the bracket 11 for passage of the bolt 25 is of elongated slot-like character so as to permit some adjustment of the bracket 11 to vary the amount and nature of the pressure applied to the bracket 11 by the roller 22.

The operation of the holddown will be readily understood from the aforegoing description in connection with the accompanying drawings. As the ladder is lowered roller 22 which is continuously pushed outwardly against the tension of the spring 20 and rides on the cam surface 13 until the latter passes the roller 22 when the latter snaps into the recess 26 formed by the cam surface 14. In this position the roller bears down on the bracket 11 to hold the ladder clamped.

The cam surface portion 14 is such that power of an amount customarily applied to elevate ladders of the character described is sufiicient to force the roller 22 outwardly of the recess 26 and unlock the ladder, the roller 22 thereafter, as the ladder is elevated, rolling under spring pressure continuously inwardly and over the asceiiding cam surface portion 13.

Thus, the ladder is automatically locked and unlocked and diependence upon manual preparation therefore is obviate What -I claim is:

l. A holddown for a ladder, said ladder having side rails and being pivotally supported at one end thereof on a truck, said holddown comprising a base member on said truck spaced from the pivoted end of the ladder, a rail-latch support secured to said base member, a latch comprising a spring-pressed roller pivotally mounted on said support for movement relative thereto, a bracket secured to the exterior face of each rail, said bracket having upper and lower reversely arranged outwardly projected cam faces with each face inclined toward its ladder rail, the upper of said cam faces being relatively short and relatively sharply inclined, the lower of said faces being relatively long and relatively gently inclined, each ladder rail and bracket moving in a plane transverse to the plane of movement of the spring pressed roller and said roller projecting into the path of movement of the bracket cam faces;

2. A holddown for ladders, characterized as in claim 1, in which the base member is a cross channel mounted on the truck roof, in which the rail-latch support is secured to and upwardly projected from the channel, and in which the rail rests upon the channel in the lowered position of the ladder.

References Cited in the file of this patent UNITED STATES PATENTS 1,831,800 Bales et al. Nov. 17, 1931 1,952,761 Larsen Mar. 27, 1934 2,615,667 Smith et a1. Oct. 28, 1952 FOREIGN PATENTS 8,805 Great Britain of 1902 193,197 Switzerland '--.f...'.-' a. Dec. 16, 1937 

